[LeArc] Forecast Discussion : MLI@ 11/16/02 2:21:44 PM

[learc@mailman.qth.net]

The following weather message is provided by McDonough County E.S.D.A.


FXUS63 KDVN 162032
AFDMLI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
232 PM CST SAT NOV 16 2002

SHARP UPPER TROUGH AXIS CENTERED OVER CWFA AT MIDDAY WITH PLENTY OF 
CLOUDS AND -SHSN OVER MAINLY CENTRAL AND NORTHEAST ZONES. SHORT TERM 
FORECAST CHALLENGE CENTERS ON CLOUD TRENDS OVERNIGHT AND CHANCES FOR 
FLURRIES OR EVEN SNOW SHOWERS THIS EVENING. 

WV AND VISIBLE SATELLITE IMAGERY...ALONG WITH KDVN 88D AND SURFACE 
WIND FIELDS SHOW DEEP CIRCULATION OVER EAST CENTRAL IA...NORTHWEST 
OF KDVN AT MIDDAY. THIS CORRESPONDED WELL WITH MODEL H5 VORTICITY 
PROGGED AREA AT 18Z. NORTH-SOUTH BANDS OF SNOW SHOWERS TO EAST 
CONTINUE WITH SOME MORNING SNOWFALL AMOUNTS OVER .5 INCHES OVER NW 
IL ZONES WHERE SLOW MOVING TROUGH HAS COMBINED WITH LINGERING 
SURFACE TO H75 LAYER MOISTURE PER MORNING KDVN SOUNDING. ETA AND GFS 
IN CLOSE AGREEMENT WITH THIS VORT MOVING EAST TO N CENTRAL IL BY 
00Z...WHICH SHOULD TAKE MOST SIGNIFICANT -SHSN EAST THIS EVENING. 
MODEL RH FIELDS KEEP H85 MOISTURE LINGERING UNTIL 06Z FROM MISS 
RIVER EASTWARD. RESULT WILL BE SOME LINGERING FLURRIES OVER EASTERN 
IA ZONES AND MAY NEED SOME SCATTERED POPS FOR IL ZONES MAINLY NORTH 
OF HIGHWAY 34 FOR EVENING. CURRENT -SHSN AT LEAST PARTLY DIURNAL IN 
NATURE AND WILL WAIT UNTIL LAST MINUTE TRENDS FOR FLURRIES VS LOW 
POPS COVERAGE FOR EVENING SNOW SHOWERS. 

OVERNIGHT...THE UPPER TROUGH CONTINUES TO SHARPEN ALONG A LAKE 
SUPERIOR TO ALABAMA AXIS. A SECOND AREA OF MID LEVEL VORTICITY SEEN 
ON SATELLITE SEEN PUSHING DOWN BACKSIDE TROUGH THROUGH CENTRAL MN AT 
MIDDAY LOOKS TO BE MAINLY CHANNELED AND NOT IMACT FORECAST AREA AS 
UPPER FLOW BECOMES N TO S. AT SURFACE...WEAK HIGH PRESSURE RIDGE 
EXTENDS SW INTO N CENTRAL IA AT MIDDAY WITH REGION IN COL BETWEEEN 
STRONG LOWS OFF SC COAST AND LEE TROUGH EXTENDING INTO N CENTRAL 
HIGH PLAINS FROM NW CAN...ALONG WITH HIGHS CENTERED OVER EASTERN CAN 
AND SW CONUS. RESULT WILL BE WEAK WIND FIELDS TONIGHT WITH DRIER LOW 
LEVEL RH FIELDS AND ANTICYCLONIC UPPER FLOW PUSHING INTO EASTERN IA.
META 2M TEMPERATURES HAD BEST HANDLE ON LOW TEMPERATURES OVER MOS 
THIS MORNING AND WILL GENERALLY FOLLOW FOR TONIGHT WITH LOWER TO MID 
20S NW TO UPPER 20S OVER SE IN W CENTRAL IL.  

UPPER SHORTWAVE RIDGING AND SUNSHINE SHOULD ALLOW TEMPS TO RECOVER 
INTO UPPER 30S TO LOWER 40S SUNDAY WITH INCREASING CLOUDS TOWARD 
EVENING AS WARM AIR ADVECTION DEVELOPS ALOFT AHEAD OF MID LEVEL 
WAVE. WILL KEEP CURRENT FLURRIES IN FOR SUNDAY NIGHT AND 
FLURRIES/SPRINKLES FOR MONDAY AS FEATURE PASSES TO NORTH AND NEXT 
COLD FRONT PUSHES THROUGH. GFS MORE AGRESSIVE AND OFF ON ITS OWN 
WITH H5 LOW DEVELOPING INTO GREAT LAKES...WHILE OTHER MODELS HAVE 
WEAKER OPEN WAVE. WILL STAY CLOSER TO MODEL CONSENSUS WITH 
FEATURE...BUT NOT GO AS WARM AS ETA MOS TEMPERATURES. NW FLOW OVER 
WESTERN CONUS RIDGE DOMINATES FROM MID THROUGH LATE WEEK WITH TEMPS 
NEAR CLIMO. WILL INTRODUCE PRECIP INTO FRIDAY NIGHT/SATURDAY 
TIMEFRAME PER LATEST GFS.   

.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

DLS